From patchwork Tue Aug 3 11:31:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Winiarska, Iwona" X-Patchwork-Id: 12416081 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5621DC4338F for ; Tue, 3 Aug 2021 11:51:54 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1FE3060BD3 for ; Tue, 3 Aug 2021 11:51:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1FE3060BD3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=94qk+yuf3c/IdlOKMl3VeXSJ1T9CCpP1w3Ga4IVZ9FA=; b=4B6Irh1VXdTbQH ADpcIFBodcH4rQ6K5DpCdxAd1w2W36ZbbDElXYYm4EvjSS0k3NyySqSjFBo7afnUR3Ljt63bQFRIY j3OAt5mleYdIlwUqZE9h3eCAOuitViJADI0I3XBJVk4h/VTW4dDWg4e2sBRlsZUO0hHw33xKxYd90 Lu1yc1PMhVHA0IErxxZpvdwpK3lsJoTeuGTrTvoYKYtj6WpLJgEDDxgRDekVwvk0h3T5Ndo4fqvMj TEZ6JIkrXys7e8D0nQPM9gJ3bTDLrY5a2x9P8YBV1MdP0Ymllbqn+VW0gMWGdEPrsmJygvxkzh9ot 3YFMQlBRwcj+WtAxU0Rw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mAsvN-002OMe-FS; Tue, 03 Aug 2021 11:49:34 +0000 Received: from mga05.intel.com ([192.55.52.43]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mAskx-002K0v-9Y for linux-arm-kernel@lists.infradead.org; Tue, 03 Aug 2021 11:38:48 +0000 X-IronPort-AV: E=McAfee;i="6200,9189,10064"; a="299248663" X-IronPort-AV: E=Sophos;i="5.84,291,1620716400"; d="scan'208";a="299248663" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Aug 2021 04:38:46 -0700 X-IronPort-AV: E=Sophos;i="5.84,291,1620716400"; d="scan'208";a="670395217" Received: from jdanieck-mobl1.ger.corp.intel.com (HELO localhost) ([10.249.128.99]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Aug 2021 04:38:40 -0700 From: Iwona Winiarska To: linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, Greg Kroah-Hartman Cc: x86@kernel.org, devicetree@vger.kernel.org, linux-aspeed@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, Rob Herring , Joel Stanley , Andrew Jeffery , Jean Delvare , Guenter Roeck , Arnd Bergmann , Olof Johansson , Jonathan Corbet , Thomas Gleixner , Andy Lutomirski , Ingo Molnar , Borislav Petkov , Yazen Ghannam , Mauro Carvalho Chehab , Pierre-Louis Bossart , Tony Luck , Andy Shevchenko , Jae Hyun Yoo , Dan Williams , Randy Dunlap , Zev Weiss , David Muller , Iwona Winiarska Subject: [PATCH v2 15/15] docs: Add PECI documentation Date: Tue, 3 Aug 2021 13:31:34 +0200 Message-Id: <20210803113134.2262882-16-iwona.winiarska@intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210803113134.2262882-1-iwona.winiarska@intel.com> References: <20210803113134.2262882-1-iwona.winiarska@intel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210803_043847_409477_833A5AA4 X-CRM114-Status: GOOD ( 17.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add a brief overview of PECI and PECI wire interface. The documentation also contains kernel-doc for PECI subsystem internals and PECI CPU Driver API. Signed-off-by: Iwona Winiarska Reviewed-by: Pierre-Louis Bossart --- Documentation/index.rst | 1 + Documentation/peci/index.rst | 16 ++++++++++++ Documentation/peci/peci.rst | 48 ++++++++++++++++++++++++++++++++++++ MAINTAINERS | 1 + 4 files changed, 66 insertions(+) create mode 100644 Documentation/peci/index.rst create mode 100644 Documentation/peci/peci.rst diff --git a/Documentation/index.rst b/Documentation/index.rst index 54ce34fd6fbd..7671f2cd474f 100644 --- a/Documentation/index.rst +++ b/Documentation/index.rst @@ -137,6 +137,7 @@ needed). misc-devices/index scheduler/index mhi/index + peci/index Architecture-agnostic documentation ----------------------------------- diff --git a/Documentation/peci/index.rst b/Documentation/peci/index.rst new file mode 100644 index 000000000000..989de10416e7 --- /dev/null +++ b/Documentation/peci/index.rst @@ -0,0 +1,16 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +==================== +Linux PECI Subsystem +==================== + +.. toctree:: + + peci + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/peci/peci.rst b/Documentation/peci/peci.rst new file mode 100644 index 000000000000..a12c8e10c4a9 --- /dev/null +++ b/Documentation/peci/peci.rst @@ -0,0 +1,48 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +======== +Overview +======== + +The Platform Environment Control Interface (PECI) is a communication +interface between Intel processor and management controllers +(e.g. Baseboard Management Controller, BMC). +PECI provides services that allow the management controller to +configure, monitor and debug platform by accessing various registers. +It defines a dedicated command protocol, where the management +controller is acting as a PECI originator and the processor - as +a PECI responder. +PECI can be used in both single processor and multiple-processor based +systems. + +NOTE: +Intel PECI specification is not released as a dedicated document, +instead it is a part of External Design Specification (EDS) for given +Intel CPU. External Design Specifications are usually not publicly +available. + +PECI Wire +--------- + +PECI Wire interface uses a single wire for self-clocking and data +transfer. It does not require any additional control lines - the +physical layer is a self-clocked one-wire bus signal that begins each +bit with a driven, rising edge from an idle near zero volts. The +duration of the signal driven high allows to determine whether the bit +value is logic '0' or logic '1'. PECI Wire also includes variable data +rate established with every message. + +For PECI Wire, each processor package will utilize unique, fixed +addresses within a defined range and that address should +have a fixed relationship with the processor socket ID - if one of the +processors is removed, it does not affect addresses of remaining +processors. + +PECI subsystem internals +------------------------ + +.. kernel-doc:: include/linux/peci.h + +PECI CPU Driver API +------------------- +.. kernel-doc:: include/linux/peci-cpu.h diff --git a/MAINTAINERS b/MAINTAINERS index 4861a214d9fe..c50d4d0005e3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14527,6 +14527,7 @@ R: Jae Hyun Yoo L: openbmc@lists.ozlabs.org (moderated for non-subscribers) S: Supported F: Documentation/devicetree/bindings/peci/ +F: Documentation/peci/ F: drivers/peci/ F: include/linux/peci-cpu.h F: include/linux/peci.h